Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: MikeW86 on August 03, 2022, 01:18:31 pm
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I'm kicking around some ideas for my next amp build. I'm interested in doing a 6G3 deluxe, but 35-40W with 5881/6L6s rather than 20W with 6V6s.
Basically a deluxe with a vibrolux power section, in a deluxe chassis and cabinet. I know I'd need to use vibrolux transformers. Comparing the schematics of the 6G3 deluxe and 6g11 vibrolux I'm noticing the vibrolux has additional reservoir filtering (two 16uf 450V caps in parallel) while the 6G3 only has one 16uf cap. Is the additional filtering needed for 6L6s or can I get away with using 6G3 filtering?
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More involved than just an extra cap. The 6G11 also has a choke. Much better B+ filtering.
The 6L6s will probably give disappointing results with the 6G3 tremolo circuit.
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sluckey.. they use the same trem circuit lol BUT! there have been complaints on it not working that great on 6L6 amps. Consider the 6G16 trem circuit.
probably also have to try both a .01 and .005 (.0047) coupling cap feeding the PI. Double check preamp voltages.
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sluckey.. they use the same trem circuit lol
Not the same. Look at the schematics.
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sluckey.. they use the same trem circuit lol
Not the same. Look at the schematics.
I need to stop replying late at night lol. Two triodes vs one? larger bias voltage swing ?
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So not a good idea, it seems. Darn.
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So not a good idea, it seems. Darn.
Idea is OK. Just needs a bit more thought.
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You could build a 6G4 Super in the Deluxe chassis with the 6G3 single tone controls and no Presensce knob.
The 6G4 Tremolo is supposed to sound good and it doesn't have the 6L6 bias trem issue mentioned above.
But, you'd need to fit in one more 12AX7 somehow.
https://el34world.com/charts/Schematics/files/Fender/Fender_super_6g4_schem.pdf
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There's also the Trem-o-Nator that could be spliced in there for trem instead of bias vary trem. Might be a big alteration though.. but then one could use 5881/6L6 family ..
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I built an amp with 6G3 preamp and 5F4 power amp. I used the 6G16 tremolo circuit though.. works fine! Very very nice amp!!! And loud enough. The 6G3 is beautiful, but lacks volume in a band context IMHO. Otherwise it would have been the perfect amp for me.
But you're right.. even tho it's a great amp, it's no 6G3 anymore.
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Hey MikeW86,
I'm just throwing out this idea because it was something I was thinking about myself...
A single channel 6G4 Super could be built in a Princeton Reverb chassis without having to drill any more holes. It has the same number of tubes and front panel control knobs. The PT opening might need to be enlarged.
And, Guitar Cabinets Direct will make a 12" PR cabinet and cover it in brown Tolex with wheat grill cloth.
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Hey MikeW86,
I'm just throwing out this idea because it was something I was thinking about myself...
A single channel 6G4 Super could be built in a Princeton Reverb chassis without having to drill any more holes. It has the same number of tubes and front panel control knobs. The PT opening might need to be enlarged.
And, Guitar Cabinets Direct will make a 12" PR cabinet and cover it in brown Tolex with wheat grill cloth.
I just shoved a single channel blond Tremolux into a Princeton Reverb chassis. PT opening will have to be enlarged quite a bit and biased toward the front and also inward in the chassis to clear the tubes, as well as allowing enough room for the chassis screws. The PT I used for my super was larger still (hammond 290BX vs 290CX in the tlux) my choke barely fit between PT and OT so it may need a new home as well, or the OT can shove over a touch.
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After some thought I've decided against the 5881/6L6 in a deluxe idea. It will mostly be a "playing at home" amp anyway, so 20W is plenty.
I do have a nice collection of NOS loctal 7C5 power tubes though, so I might build it with loctal sockets to use those instead of 6V6GTs, since internally they're the same tube, with a different pinout.
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I've got a bunch of nos 7C5 tubes as well and made adapters with loctal tops and octal bottoms. I was warned that they won't handle too much plate voltage compared to a 6V6GT and in my Deluxe with a 5AR4 one of them died. So if I want smooth lower volume I swap in a 5Y3 with the 7C5 and use a 5AR4 with the 6V6GT JJ's when I want volume etc. Sorry I can't quote max Va for both etc at the moment. Good luck with your project.
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Specs are the same for 7C5 and 6V6GT according to the tube manuals.
My RCA manual says max plate voltage for 6V6GT is 315V, obviously they can handle more than that.